Gravity operated door hinge



Dec. 15, 1970 J. s. BOOTH O 3,546,736

GRAVITY OPERATED DOOR HINGE Filed Aug. 19, 1968 INVENTOR:

JOHN S. BOOTH ATTOR N EYS United States Patent 3,546,736 GRAVITYOPERATED DOOR HINGE John S. Booth, 3314 Fairview, Dallas, Tex. 75229Filed Aug. 19, 1968, Ser. No. 753,422 Int. Cl. Ef 1/07 US. Cl. 16-153 4Claims ABSTRACT OF THE DISCLOSURE A gravity operated door hingeincluding a lower fixed member having a sleeve surrounded by a pair ofupstanding, helical, inclined, camming shoulders and an upper rotatingmember having a stud mating with the lower member sleeve and helicalupper camming surfaces engaging the camming shoulders. The uppercarnming surfaces are positioned so that they engage the inclinedcamming shOulders when the door is closed, to provide positive pressureseating the door in its closed position. The camming shoulders have aflat portion at their upper ends, so that when the door is opened widethe camming surfaces are in engagement therewith to eliminate the torquepressing the door towards the closed position.

BACKGROUND OF THE INVENTION Field of the invention This inventionrelates to door hinges, and more particularly, to gravity-operated doorhinges fgr one-way swinging doors which are biased to the closedposition.

Prior art It has been known to provide a two-piece door hinge havingcoacting helical camming tracks. The weight of the door on the uppermember of. such a hinge causes the upper member to be urged downwardaround the camming track or the lower member, thus closing the door.

Such hinges in the prior art have not, however, provided for a positivepressure against the door in the closed position. It may be desired toprovide such pressure in any number of applications. For example, adefinite sealing of the closure is desired for the doors of arefrigerating unit.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide a gravity hinge having coacting camming surfaces which willexert a continuous pressure tending to retain a door in its closedposition. In one aspect of the invention, the camming surfaces arealigned so that the upper cam rests on inclined portions of the lowercam when the door is closed, thus creating a rotational moment pressingthe door in place.

In a further aspect of the invention, the camming surfaces of a hingeare so shaped that, when the door is opened wide, the rotational torquetending to close the door is eliminated.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding ofthe present invention and for further objects and advantages thereof,reference may now be had to the following description taken inconjunction with the accompanying drawings in which:

FIG. 1 is a plan view of the fixed member of a twopiece hinge embodyingthe present invention;

FIG. 2 is a plan view of the rotating member of the same hinge;

FIG. 3 is a plan view of the hinge of FIGS. 1 and 2 in operatingposition on a door, with the door closed; and

3,546,736 Patented Dec. 15, 1970 DESCRIPTION OF A PREFERRED EMBODIMENTThe fixed member of the hinge, indicated generally by the referencenumeral 10 in FIG. 1, has a mounting plate 12 having a sleeve 16extending outwardly therefrom. A hole 14 is provided in the plate 12 atthe center of the sleeve 16. Situated circumferentially about sleeve 16are two matched upstanding shoulders 18:: and 18b. The upper surfaces ofshoulders 18a and 18b are inclined, so that they form generally helicalcamming tracks. Located at the upper ends of the camming tracks formedby shoulders 18a and 18b are fiat surfaces 20.

The mounting plate 12 is provided with holes 22 so that suitablemounting means such as screws may be used to fasten the plate to a flooror other fixed frame defining an aperture to be closed by a door.

The rotating member of the two-piece hinge, generally indicated by thereference numeral 24 in FIG. 2, has a mounting bracket 26, from which astud 28 extends. The stud is dimensioned so that it fits slidably androtatably into sleeve 16.

Arrayed about stud 28 are two raised camming surfaces 30a and 3011 whichare complementary to camming shoulders 18a and 18b. These upper cammingsurfaces 300: and 30b are inclined so that they can ride on the cammingtracks presented by shoulders 18a and 18b.

The bracket 26 is provided with holes 32, so that the bracket may besecured to a door by suitable fastening means. The member 24 is providedwith a vertical extension 33, through which a screw may be threaded toprovide additional bracing of the member 24 to the door.

The fixed member 10, as well as the rotating member 24, may be ofunitary construction, formed from a single piece of a suitable materialsuch as a plastic.

In operation, as illustrated by FIGS. 3 and 4, the fixed member 10 isattached to the lower part of a frame 34 defining a door opening, andthe rotating member 24 is secured to the lower corner of a door 36adjacent the side of the door to be pivoted. The stud 28 is positionedwithin sleeve 16, so that relative rotation and axial movement ispermitted between fixed member 10 and rotating member 24. The weight ofthe door upon the fixed member 10 constantly urges the camming surfaces30a and 30b downward against the camming shoulders 18a and 18b. As therotating member 24 moves downward along the camming shoulders 18a and18b, it also rotates to close the door to which it is attached. Thus,when the door is open, the force of gravity acting on the door producesa torque about the stud 28 tending to cause the door to close.

An important feature of the invention is the rotational alignment of thecamming surfaces 30a and 30b with respect to the upstanding shoulders18a and 18b, and with respect to the door. This alignment is such that,when the door has been rotated into its closed position, the cammingsurfaces 30a and 30b have not completely traveled downward along thecamming shoulders 18a and 18b to rest on the mounting plate 12, as shownin FIG. 3.

Thus, when the door is closed, the weight of the door transmittedthrough the camming arrangement exerts a constant pressure retaining thedoor in its closed position. This condition is indicated in FIG. 3,which shows a gap 38 between the camming surface 30 and the mountingplate 12.

The device is also constructed so that the door to which the hinge isattached may be swung wide to a point where the bias exerted through thecamming arrangement is eliminated. When the door is opened Wide enoughto place the camming surfaces 30a and 30b in contact with only the flatsurfaces 20, as shown in FIG. 4,

no rotational torque about the stud 28 is created by the weight of thedoor. Thus the door is freed from the bias normally exerted through thehinge.

A suitable stop, not shown, restraining the door from rotation beyondthe point at which the surfaces 30a and 30b rest on the flat areas 20should be provided. Such a stop serves to prevent the surfaces 301: and30b from dropping off shoulders 18a and 18b onto the plate 12.

Having described the invention in connection with certain specificembodiments thereof, it is to be understood that further modificationsmay now suggest themselves to those skilled in the art and it isintended to cover such modifications as fall within the scope of theappended claims.

What is claimed is:

1. A gravity operated hinge for rotatably mounting a door in a frame tobe closed against a door jam, comprising:

a fixed hinge member adapted for attachment to the frame and having abase, a vertically extending sleeve, and an upstanding generally helicalcamming shoulder terminating at a slope to the base at a first anglewith respect to the longitudinal axis through said member around saidsleeve, and

a rotatable hinge member adapted for attachment to said door and havinga vertically extending stud slidably mountable in said sleeve andhelical camming surfaces terminating at a leading edge at a second anglewith respect to the longitudinal axis of said member greater than thefirst angle to engage said camming shoulders such that when said door isclosed the camming surfaces engage the fixed hinge member on inclinedportions of said-shoulder.

2. The combination of claim 1 wherein upper portions of said cammingshoulders are perpendicular to the axis of said sleeves.

3. A gravity operated hinge for rotatably mounting a door in a frame toclose against a door jam, comprising: a fixed hinge member adapted forattachment to the frame and having a base, a vertically extendingsleeve, and a pair of upstanding generally helical camming shoulderscircumferentially about and formed as a part of said sleeve andterminating at a slope to said base at a first angle with respect to alongitudinal axis through said member, and a rotatable hinge memberadapted for attachment to said door and having a vertically extendingstud slidably and rotatably mounted in said sleeve and a pair ofupstanding generally helical camming surfaces arrayed about anddisplaced from said stud in a manner to produce a rotating movement onsaid door, said camming surfaces terminating at a leading edge at asecond angle with respect to the longitudinal axis of said membergreater than the first angle to cause engagement with said cammingshoulders such that when said door is closed the camming surfaces engagethe fixed hinge member on inclined portions of said shoulders.

4. A gravity operated hinge for rotatably mounting a door in a frame asset forth in claim 3 including means to reduce the rotating moment onsaid door to zero when in a wide open position.

I References Cited UNITED STATES PATENTS 2,904,824 9/1959 Kuehl 16-1533,083,402 4/1963 Foltz 16-153 3,113,649 12/1963 Wargo 16153 3,398,8814/1968 Hentzi et a1. 16-153 3,398,487 8/1968 Mtyas 16153 BOBBY R. GAY,Primary Examiner D. L. TROUTMAN, Assistant Examiner UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 3, 546 ,736 Dated December15 1970 lnvgntofls) John S Booth It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Column 1, line 38, "or" should read of Column 3, line 37, "sleeves"should read sleeve Column 4, line 33, "3 398 ,881" should read 3 ,378,881

Signed and sealed this 4th day of Ma 1 1971 (SEAL) Attest:

EDWARD M FLETCHER ,JR WILLIAM E SCHUYLER, JR Attesting OfficerCommissioner of Patents

